This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: How long did it take for oxygen to build up in the Earth's atmosphere to its present levels? A) ... (Read 75 times)

809779

  • Hero Member
  • *****
  • Posts: 579
on: Jul 27, 2018
How long did it take for oxygen to build up in the Earth's atmosphere to its present levels?
 
  A) at least 542 million years
  B) at least 360 million years
  C) at least 2 billion years
  D) at least 3.5 billion years

Question 2

Express the following number to three significant figures: 21.25 m
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

blakeserpa

  • Sr. Member
  • ****
  • Posts: 338
Reply #1 on: Jul 27, 2018
Answer to Question 1

C

Answer to Question 2

21.3 m


809779

  • Member
  • Posts: 579
Reply 2 on: Jul 27, 2018
Wow, this really help

chjcharjto14

  • Member
  • Posts: 342
Reply 3 on: Yesterday
Great answer, keep it coming :)

« previous next »
 

Did you know?

The strongest synthetic topical retinoid drug available, tazarotene, is used to treat sun-damaged skin, acne, and psoriasis.

Did you know?

More than one-third of adult Americans are obese. Diseases that kill the largest number of people annually, such as heart disease, cancer, diabetes, stroke, and hypertension, can be attributed to diet.

Did you know?

Disorders that may affect pharmacodynamics include genetic mutations, malnutrition, thyrotoxicosis, myasthenia gravis, Parkinson's disease, and certain forms of insulin-resistant diabetes mellitus.

Did you know?

People with alcoholism are at a much greater risk of malnutrition than are other people and usually exhibit low levels of most vitamins (especially folic acid). This is because alcohol often takes the place of 50% of their daily intake of calories, with little nutritional value contained in it.

Did you know?

Today, nearly 8 out of 10 pregnant women living with HIV (about 1.1 million), receive antiretrovirals.

In acute otitis media, the tympanic membrane is usually bulging and purulent fluid is present in the In acute otitis media, the tympanic membrane is usually bulging and purulent fluid is present in the
Close-ups of Jupiter’s Atmosphere Close-ups of Jupiter’s Atmosphere
Long-Term Potentiation Long-Term Potentiation
This chart illustrates the four quadrants in which we can place the relationships between the state This chart illustrates the four quadrants in which we can place the relationships between the state
How Does Earth Work? Physical Geology and the Process of Science, 2nd Edition How Does Earth Work? Physical Geology and the Process of Science, 2nd Edition
How long does exercise affect blood sugar? How long does exercise affect blood sugar?
Video: Language Areas Animation

For a complete list of videos, visit our video library